Tap testing canning technique - GIF

[ToolTalkBot]

Tap testing canning technique.





Previously:

Jet engine testing
Model T Ford testing
Testing a crash barrier
Testing asphalt porosity
Testing different anchors in sand
Testing different types of foam rubber

[Gadgeteer]

Huh? Is there a point to this?

[IntheGroove]

Huh? Is there a point to this?

Yes, botulism...

[ductape]

Huh? Is there a point to this?

It is a way to determine if canned food is still good or not. A properly sealed jar will create a vacuum and draw the lid down into a convex shape while it cools after the hot bath or pressure cook. It will make a different sound than an unsealed jar when tapped with a spoon. An unsealed jar is likely to get very bad bacteria growing in it, as stated above. Most people who do this write the date it was processed on the lid.

She said "lying liar" after holding the jar up to the light after it failed the tap test. The lid appeared to have sealed but was probably bent or otherwise defective. Unless it was freshly canned, it isn't worth the risk. Throw it away.

[Gadgeteer]

It is a way to determine if canned food is still good or not. A properly sealed jar will create a vacuum and draw the lid down into a convex shape while it cools after the hot bath or pressure cook. It will make a different sound than an unsealed jar when tapped with a spoon. An unsealed jar is likely to get very bad bacteria growing in it, as stated above. Most people who do this write the date it was processed on the lid.

She said "lying liar" after holding the jar up to the light after it failed the tap test. The lid appeared to have sealed but was probably bent or otherwise defective. Unless it was freshly canned, it isn't worth the risk. Throw it away.

Pushing down on the lid will accomplish the same test for sealing. No need for the tap. I test my canned bottles of chokecherry syrup, after pasteurizing, and none have failed the test.